Highly sensitive biosensor based on aptamer and hybridization chain reaction for detection of cadmium ions

Abstract

In this work, a highly sensitive biosensor for detecting cadmium ions (Cd2+) was developed based on a Cd2+‐specific DNA aptamer and a hybridization chain reaction (HCR). The Cd2+ aptamer (named S0) was used to recognize Cd2+ and trigger the HCR. Without Cd2+, S0 initiated the HCR to form long nicked dsDNA structures to quench the fluorescence. Then, Cd2+ could bind with S0 to block HCR to recover fluorescence. This biosensor had high sensitivity with a detection limit of 0.36 nM and a linear range from 0 to 10 nM. Moreover, it showed a satisfactory selectivity and recovery rates.

Recent Aptamer-Based Biosensors for Cd2+ Detection

“…CAO-1 was utilized as a promoter for HCR and a Cd 2+ −specific aptamer, while CAO-15 and CAO-16 were subjected to heating and cooling to form a hairpin structure, respectively. BHQ1 was used to label CAO-15, whereas 5-carboxyfluorescein (FAM), which can emit fluorescence, was used to label CAO-16 [ 58 ]. In the absence of Cd 2+ , a pulse on the HCR by CAO-1 will form long-nicked dsDNA structures.…”

“… ( a ) Principles of the biosensor detection of Cd 2+ [ 58 ]; ( b ) Illustration of a Cd 2+ biosensor based on DNAzyme-dependent Mg 2+ [ 59 ]. ( c ) Diagrammatic sketch of monitoring Cd 2+ by toehold combination and branch migration.…”

Nanomaterial-Based Fluorescent Biosensor for Food Safety Analysis

“…Cd(II) is a heavy-metal contaminant that can have chronic effects on humans. To increase the sensitivity of Cd 2+ detection, Xu et al used an HCR-assisted DNA amplification strategy involving a Cd 2+ -specific DNA aptamer for Cd 2+ sensing [ 99 ]. The Cd 2+ aptamer (S0) was used to recognize Cd 2+ and trigger the HCR.…”

Enhanced biosensing of tumor necrosis factor-alpha based on aptamer-functionalized surface plasmon resonance substrate and Goos–Hänchen shift

“…These favourable features of aptamers have made them valuable elements in sensing technologies, particularly those employing optical readouts. [13][14][15][16] Among which, surface plasmon resonance (SPR)-based transducers, have gained increasing attention for their ability to enable biomolecular detection in a simple, fast, and real-time manner. 17 Traditional aptamer-based SPR biosensors often operate through two mechanisms: bindinginduced aptamer structural changes producing an 'on' signal upon target recognition, or competitive binding causing strand displacement.…”